package com.itheima.demo01.Map;

import java.util.HashMap;
import java.util.Hashtable;

public class Demo05Hashtable {
    public static void main(String[] args) {
        HashMap<String, String> map = new HashMap<>();
        map.put(null, "a");
        map.put("b", null);
        map.put(null, null);
        System.out.println(map);
        Hashtable<String,String> table=new Hashtable<>();
        table.put(null, "a");
        table.put("b", null);
        table.put(null, null);
        System.out.println(table);
    }
}
